Mobile Terminals (MT), and in particular, MTs which are defined in accordance with the Global System for Mobile Communications (GSM) General Packet Radio Service (GPRS) are configured to enable user application programs, related software, routines and the like, to run on external Terminal Equipment (TE). Terminal equipment may be defined generally, for example, as any equipment fitting the definition of telecommunications terminal equipment as would be known to those of skill in the art. TE may include for example, computer equipment, LAN terminals, modems, routers, bridges, modules, or the like containing wired or wireless interfaces, such as cellular radio terminals, cellular radio base stations including Global System Mobile (GSM), 3rd Generation (3G) terminals and base stations, satellite earth station equipment such as Ship Earth Station (SES), and the like.
A typical MT may be connected to TE across a reference point (R interface in various standards), connection, arc, edge, or the like, and supports dial-up networking sessions, typically Internet Protocol (IP) based, with a service provider. It will be appreciated that the phrase “dial-up” refers to a modem type connection between the MT and TE using, for example, standard modem commands, and not to the manner in which the remaining portions of the session proceeds, which, as will be appreciated, is in accordance with various communications protocols including wireless protocols. A connection between the MT and TE is typically established using a data link layer protocol, and frequently, the data link layer protocol of choice is the Point to Point Protocol (PPP). The TE transport layer protocol is typically the Internet Protocol (IP) at the network layer. As is known to those of ordinary skill in the art, the PPP protocol is used for managing and controlling the data link across the TE to MT interface R. In addition MT and TE may communicate using standard AT modem commands further in accordance with specifications such as GSM, IS-136, and the like.
During conventional operation, the establishment of a connection using PPP typically proceeds in 3 stages: establishment of Link Control Protocol (LCP), Authentication including Password Authentication-PAP or Challenge Handshake Protocol-CHAP, and establishment of Network Control Protocol, typically the Internet Protocol Control Protocol (IPCP). For the PPP link to be successfully established, each of the above stages needs to be established by way of actions, negotiations, and the like which, according to the protocol specifications, must take place within certain time intervals, and under other time related constraints, capacity related constraints, acknowledgement constraints, re-transmission constraints and the like. It should be noted that, for example, the retry count and time period are not always configurable by an MT, subscriber, or the like, and may generally be implementation dependent inhibiting in many cases global pre-configurations, adaptability, or the like.
A GPRS MT may support applications running on an external TE device and using packet based data transfer. As noted above, a GPRS MT may provide a means to establish a link-layer connection between and with the TE and, for example, a network, which connection proceeds using PPP, as described for example in the Internet Engineering Task Force (IETF) document RFC 1661 and 1662: “The Point-to-Point Protocol (PPP)” (STD 51) (1994). The TE and MT may further use Internet Protocol Control Protocol (IPCP). IPCP is responsible for configuring, enabling, and disabling the IP protocol modules on both ends of a PPP link using the same packet exchange mechanism as the Link Control Protocol (LCP). IPCP packets may not be exchanged until PPP has reached the Network-Layer Protocol phase. IPCP packets received before this phase is reached should be silently discarded. Typically, each IPCP packet exchanged between the TE and the MT, has a timeout period set by the TE as 3 seconds and a maximum number of re-tries to 10. Accordingly, at the end of 30 seconds, a TE can bring a link down if there is no response by the IPCP peer. During IPCP, when an MT is configured for a PDP type IP session, the MT attempts to obtain a valid IP address from the network during context activation which can take up to 150 seconds.
Problems arise however in that, as noted, if context activation takes longer than the total timeout, the TE can bring down the link. As noted the timeout values and number of re-tries may not be configurable by the TE. In such cases, where values are not configurable, the link may be inhibited from being set up correctly.